The present invention relates to a vacuum cleaner nozzle mechanism having a sliding base with a suction or intake opening, a suction conduit connecting means for a vacuum cleaner, an air feed channel for establishing communication between the intake opening and the connecting means, and a turbine that is driven by drawn-in air and serves to drive a brush roller that is rotatably mounted in the vicinity of the intake opening.
Not only for the vacuum cleaning of textile floor coverings, but also for cleaning smooth floor surfaces, the force of the air stream that is flowing into the vacuum cleaner nozzle mechanism is not adequate for loosening dirt particles that adhere to the surface that is to be cleaned. For this reason, a mechanical action, preferably via a rotating brush, is necessary, especially for cleaning textile floor coverings. This rotating, roller-like brush can be driven not only by an electric motor as well as by a friction gear, or by an air turbine. Where an air turbine is used, the intake air stream that flows through the nozzle mechanism is utilized to drive the turbine wheel, which is mounted in a turbine chamber. The rotation of the turbine wheel is transferred directly to the roller brush via a belt drive. Driving the rotating brush roller via an air turbine is particularly advantageous, since air turbines have a very straightforward construction and hence are very economical, and the air stream that is required for driving the turbine is available as the intake or suction air stream. In contrast, with an electric drive system, in addition to the expense for the electric motor, there also exists the problem of not only providing power from the vacuum cleaner to the nozzle mechanism, but also doing so in an absolutely safe manner.
These reasons have led to the significant use of air turbines for driving the rotating brush roller. Unfortunately, heretofore known vacuum cleaner nozzle mechanisms have the shortcoming that the drive power of the air turbine is frequently significantly reduced due to the fact that the intake opening of the nozzle mechanism rests very tightly i.e. in a nearly sealing manner on the floor surface that is to be cleaned, especially with textile floor coverings, thereby greatly reducing the suction or intake air stream that is trying to flow in. In addition, the contact pressure of the nozzle mechanism against the surface that is to be cleaned is increased by the partial vacuum that builds up in the suction region, as a result of which the intake air stream that is flowing in through the suction or intake opening is restricted even further, so that the turbine wheel, and hence the brush roller that is to be rotated, frequently cease to rotate, thereby preventing any mechanical cleaning action.
With the heretofore known vacuum cleaner nozzle mechanisms that have a rotating brush roller, the speed of the rotating brush roller can be varied, even to the point of stopping the roller, by deflecting the air stream that is flowing onto the turbine wheel.
Due to the forward and backward operating movements of the nozzle mechanism during a cleaning process on the floor surface that is to be cleaned, and due to the often varying surface condition and density of the textile floor covering, the intake air stream that is flowing through the suction or intake opening into the nozzle mechanism constantly fluctuates, as a consequence of which the rotational performance of the brush roller, and hence the cleaning capacity thereof, is unsatisfactory, which the person that is operating the vacuum cleaner frequently cannot immediately recognize.
It is therefore an object of the present invention to provide a vacuum cleaner nozzle mechanism of the aforementioned general type that, regardless of the floor condition and the distance between the sliding base and the floor, always allows an adequate suction or intake air stream to flow in for driving the air turbine in the turbine chamber.